TITLE: GCN CIRCULAR NUMBER: 29661 SUBJECT: Fermi GRB 210317A: Global MASTER-Net observations report DATE: 21/03/17 18:15:09 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 210317A ( Fermi GBM team, GCN 29659) errorbox 30510 sec after notice time and 30572 sec after trigger time at 2021-03-17 17:38:01 UT, with upper limit up to 18.2 mag. Observations started at twilight. The observations began at zenith distance = 46 deg. The sun altitude is -10.1 deg. The galactic latitude b = -7 deg., longitude l = 288 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1570432 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 30602 | 2021-03-17 17:38:01 | MASTER-SAAO | (10h 12m 01.88s , -63d 59m 59.4s) | C | 60 | 17.3 | 30682 | 2021-03-17 17:39:21 | MASTER-SAAO | (10h 20m 18.77s , -66d 00m 32.2s) | C | 60 | 17.5 | 30842 | 2021-03-17 17:42:00 | MASTER-SAAO | (10h 05m 27.61s , -62d 00m 11.5s) | C | 60 | 17.5 | 31081 | 2021-03-17 17:45:59 | MASTER-SAAO | (10h 30m 43.04s , -68d 00m 41.0s) | C | 60 | 18.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.